Repeating cycle igniter control



April 8, 1958 R. E. MEYER REPEATING CYCLE IGNITER CONTROL 2 Sheets-Sheet1 Filed NOV. l5, 1952 INVENTOR ROBERT E. MEYER AGENT 2 Sheets-Sheet 2Filed NOV. 15, 1952 INVENTOR noaa-Pr E. MEYER By 1 j C74 AGENT REPEA'HNGCYCLE IGNITER coNrnoL Robert E. Meyer, Glastonbury, Conn., assigner toUnited Aircraft Corporation, East Hartford, Conn., a corporation ofDelaware `Application November 15, 1952, Serial No. 320,653

12 Claims. (Cl. 60---35.6)

This invention relates to an improvement in igniter controls for usewith a turbojet engine having an afterburner for igniting saidafterburner.

An object of this invention is to provide an igniter which willautomatically repeat the injection of an afterburner igniting fuelcharge to assure afterburner ignition during an afterburner startingcycle.

Another object of this invention is to sense an afterburner ameout andautomatically inject, in repeating cycles, an afterburner igniting fuelcharge until afterburner ignition occurs. l l

A further object of this invention is to time the frequency of repeatingigniter cycles to prevent overheating of parts affected by the ignitercharge combustion.

Other objects and advantages will become apparent from `the followingspecification and drawings.

In the accompanying rawings there is illustrated a suitable mechanicalembodiment for the purpose of disclosing the invention. The drawings,however, are for the purpose of illustration only and are not to betaken as limiting or restricting the invention. t will be apparent tothose skilled in the art that various changes in the illustratedconstruction may be made` without exceeding the scope of the invention.A portion of this igniter is shown and claimed in co-pending ApplicationSerial No. 196,426 of Richard J. Coar, tiled November 18,` 1950, nowPatent No. 2,819,587 issued January 14, 1958.

Fig, 1 is a schematic view of a turbojet engine including an afterburnershowing the control system for said afterburner.

Fig. 2 is an enlarged view in section of the igniter control of theafterburner control system.

The turbojet engine 2 has a compressor 4, which, in the arrangementshown, is a centrifugal type, driven by a turbine 6. Combustion chambers8 therebetween deliver air from the compressor to the turbine. Anafterburner 10 is attached at the turbine outlet to provide a means ofincreasing the thrust.

The engine 2 has two axially-spaced annular intake openings 12 to directthe incoming air into the two oppositely facing annular compressorinlets. Compressed air discharging from the compressor 4 passes to theturbine through the combustion chambers 8 where it is mixed with fuelfrom fuel nozzles 14. These fuel nozzles 14 receive fuel from thegovernor 15 through Conduit 20. The fuel-air mixture is initiallyignited within the combustion chambers 8 by a spark igniter 16. Thegovernor '15 maintains the rotative speed of the turbine rotor assembly`in accordance with the value selected by the power lever 17 bycontrolling fuel ow supplied through conduit and nozzles 14 to thecombustion chambers 8.

From the turbine, the gases pass around a cone 18 into the diffusersection 19 of the afterburner. When the afterburner is operating, fuelis discharged into these gases from a plurality of fuel nozzles 26located in the diffuser 19.

Since the gases leaving the turbine 6 con-` tain considerable unburnedoxygen, the additional fuel introduced by fuel nozzles 26 provides acombustible mixture which may be initially ignited within combustionchamber 27 by ignition means hereinafter described. The burning of thiscombustible mixture is stabilized in the afterburner combustion chamber27 by flameholders 30 and 32. The burned gases discharge from the enginethrough the variable area nozzle 44.

The variable nozzle 44 operates between a minimum opening for engineoperation without afterburning and a maximum opening for operation ofthe engine with afterburning. A nozzle and actuating system, similartothe one shown with this invention, is shown and claimed in co-pendingapplication Serial No. 193,734 of Frederickv `car 140, and a trackmechanism 142 for said car.

The afterburner control system can be divided into three main parts, (l)the fuel system, (2) the ignition means and (3) the exhaust nozzleactuator control. These three parts are closely coordinated by fluidconduit connections and an electrical system.

The fuel system includes the fuel tank 46, the fuel booster pump 48, thefuel pump 50, the fuel meter 52 and the fuel nozzles 26. The fuelbooster` pump 48 is mounted on the fuel tank 46 and is connected to thefuel pump 50 by conduits 54 and 56. The fuel pump 50 shown is of thetype having a centrifugal impeller driven by a compressed air turbine.Compressed air supplied from the compressor outlet of the engine drivesl rotor 58, the air being delivered to intake passage 60 in which therotor is located by conduits 230, 64 and 66 and discharged throughpassage 62.- A valve operated by electric motor 68 is located at thejunction of conduits 64 and 66 to control the operation of the fuel pumpby regulating the flow of compressed `air to rotor 58. The rotor isconnected to and drives centrifugal irnpeller 70 which pumps fuel tofuel meter 52 through conduit 72. The fuel meter 52 meters the fueltherein and injects it into the engine through conduit 74 and nozzles26. The fuel meter represented herein may be any one of many types someof which are shown and claimed in copending applications Serial No.196,423 of Richard I. Coar, led November 18, 1950, and Serial No.196,414 of Robert N. Abild, tiled November 18, 1950, now

Patent No. 2,714,803 issued August 9, 1955.

The exhaust nozzle actuator control 76 is a device to divert a pressureto the exhaust nozzle actuating cylinders 130 either to open or to closethe exhaust nozzle as required. Compressed air from the compressor 4 isdelivered to the nozzle control 76 by conduit 230 to provide theoperating pressure. Conduit 262 connects the nozzle control to the sideof the cylinders nearest to the nozzle which causes the nozzle to openwhen the operating pressure is applied thereto and conduit 266 connectsthe nozzle control to the side of the cylinders 130 farthest from thenozzle which causes the nozzle 44 to close when the operating pressureis applied thereto. Turbine exhaust gas static pressure which isdelivered to the control 76 by conduit 79 automatically controls thisnozzle control 76 to connect conduit 230 to either conduit 262 or 266.An exhaust nozzle actuator control of this type is shown and claimed incro-pending application Serial No. 196,424 of Richard l. Coar, filedNovember 18, 1950, now Patent No. 2,715,311 issued August 16, 1955. v

The igniter control 28 injects an amount of fuel in addition to thatnormally supplied into a combustion chamber 8 where it is ignitedresulting in flame propagation through the turbine into the afterburnerfor igniting Patented Apr. `8, 1958 a combustible mixture in theafterburner. Fuel is provided to the igniter control 28 from theafterburner fuel system by conduit 174.

Igniter control 28 has a housing 1134i (see Figure 2) with a cover 11i?,mounted on one end by bolts 15M. A bore 186 is provided in said housinghaving its end covered by cover 102 connected to passage 1143 whichconnects to a conduit 115, which is shown as carrying compressordischarge pressure.

The housing 18@ also has two bores 116 and. 113 of different diameterswhich are co-aXially aligned, one end of the smaller bore 118 extendinginto bore 116 through an inner cylindrical ilange 119. The other end ofbore 11S is closed by housing 188. Cover 182, closes the openingpresented by bore 116.

i A piston member .l2/i is mounted within bere 'l ing a skirt 126slidably engaging said bore. Proiecticns 128 permit the end of pistonmember 124 to form a cham* ber 123 with cover 102 when piston 124 is inits extreme left position (see Fig. 2). A passage 131 connects chamber123 to bore 106.

A piston member 125, with a bore 12'? therein, has a slidable l'lt inbore 118 and extends out of inner cylindrical flange 119 into a. chamber136, v-.fhich is formed by said flange 119, piston member 124, and bore116. Chamber 136 is connected to reference pressure through opening 137and conduit 139. A spring seat 129 is formed on the end of piston member125 in chamber 136. A spring 133 is seated at one end around cylindricalflange 119 against the end of bore 116 and at its other end againstspring seat 129. This spring biases piston mem bers 124 and 125 to theleft, piston member 1135 against piston member 124 and the projections128 of piston member 124l against cover 1112, thereby forming a cham--ber 141 at the right end of bore 113 between housing ldd and the end ofpiston member 125. A bushing 1151i h ing an orifice 144 is threaded intoan opening 126 n pi ha vi, ton member 124. This orifice connects chamber123 with chamber 136 through holes 135 in piston 12S.

A piston member 148 is slidably mounted in here and biased by a spring15@ to the right against the heus-- ing 100. A bore 152 extends into theleft end ot i member 148 and is connected by passages 154i to an annulargroove 156 around said piston member. "l'his annular groove 156 is alsoconnected to passage 13"? said piston member is positioned to the leftin Fig. 2. A second annular groove 158, and a third annular groove 160,are formed around piston member M8. A f.. 162 connects annular groove168 to a passage 161i in piston member 148 which in turn is connected toa chamber 166 formed at the right end of piston 11th beni/ecn saidpiston and housing 10d. A bushing 16S with a restricting orice 170. ismounted in passage 16a.

Housing 10d has another bore 38h formed therein, one end of the borebeing closed by said housing and the other end being closed by a cover502. Cover 3G12 is held on by bolts 304. A passage 366 connects thelleft end ol' bore 300 to passage 131. Cover 3G12 has a circular portion308 which extends into bore 38d and has a slidable fit therewith. A hole310 in said circular portion 363 connects passage 306 to the interior ofthe circular portion.

A piston member 312 is slidably mounted in here and biased by a spring314 to thc lett against the circular portion 308 of the cover 362 whichforms a stop. annular' groove 316 extends around said piston. Aventwould not start to close until a two second passed from the timethat an operatingl pr reached the oriiice. This time of delay is set tobe some value over the time required for an actuating pressure to reachthe right side of piston member 312.

A passage 1'72 in housing 10) connects annular groove 153 ot" pistonmember 148 with annular groove 316 of piston member 312 when pistonmember 312 is in its position against stop 308. ln this same position ofpiston member 312, a passage 318 connects annular groove 316 withconduit 174, which delivers fuel from the afterburner fuel system, Whenpiston member 312 is positioned to the right against the end of bore 300it closes conduit 172 and passage 318 Where they enter said bore.Conduit 326 connects the right end of bore 300 to conduit 262, whichconnects the nozzle control to the side of the cylinders 130 nearest tothe nozzle which causes the nozzle to open when the operating pressureis applied thereto.

A passage 176 in housing 1th? connects annular groove 158 to chamber1411 when piston member 143 is in its spring biased position, to theright in Fig. 2 and pistou 125 is in its spring biased position, to theleft in Fig. 2. A passage 178 in housing 100 connects chamber 141 toannular groove 161) on piston member 168 in any posi tion of pistonmember 148 or piston member 125.

A passage 180 in housing 1d@ having a bushing 182 with a restrictingorifice 18d therein connects annular groove 161i on piston member 148with conduit 186 when piston member M8 is in its spring biased position,to the right in Fig. 2. Conduit 186 is a connection to drain. Forconvenience it is shown attached to the afterburner. An annular groove188 in housing ititl around here 106 is connected to a conduit 19d todirect fuel to a cornbusu tion chamber 8 through a nozzle 191. Thisgroove 188 is connected to annular groove 161') of piston member 148when said piston member is positioned to the lett in Fig. 3.

Annuler grooves 192 and 194 in housing 1in! around bore 148, and annulargroove 1% in housing lo@ around bore 118 are so positioned to preventleakage along said bores between different pressures or" like lluids andbetween different liuids. These grooves are interconnected by passages198 and 281B. A passage Ztl?v connects these grooves to conduit 264which may go to drain. Annular groove 266 around piston 125 in bore '118is connected by passage 268 to compressor discharge pressure conduit115. Groove 2616 then having a higher pressure than the drain pressurein groove 1916 prevents llow from groove 196 into chamber 136.

The electrical system may include a temperature control amplifier 86which during afterburner operation is sent a signal by thermocouples 88which sense turbine discharge temperature. Therinocouplcs also senseturbine temperature but send their signal to temperature gage 92. Thisamplifier when energized sends a signal t the fuel meter 52 to attenuatefuel flow in accordance with turbine discharge temperature and controlsthe operation of a normally closed solenoid operated shut-Off valve inthe fuel meter 52. The aftcrburner switch 94 controls the amplifier 86,sets the motor operated valve 68 and controls the fuel booster pump 48.

Operation Afterburner operation is initiated by placing switch 94 in itson position. This movement energizes the temperature control amplierwhich in turn opens a nermally closed solenoid operated shut-off valvein the fuel meter and sends a signal to the afterburner fuel meter forattenuating fuel' flow therethrough. This movement oi` the switch alsoplaces motor operated valve 68 in open position and starts the fuelbooster pump 48.

The operation of the fuel booster pump.v forces fuel from the fuel tank46 through conduits 54 and 56 to the impeller '70 of the fuel pump 50.The opening of the motor operated valve 68 allows compressed air to bedirected' from the outlet of the engine compressor 4 through conduits230, 64 and 66 against turbine 58 to.` drive the imasesinan peller 70.The impeller 70 then delivers fuel to the afterburner fuel meter 52.This fuel meter 52 meters fuel under the influence of compressorpressure rise and the temperature control amplifier and this fuel passesby a normally closed solenoid shut-off valve, which is now open, throughconduit 74 to the fuel nozzles 26.

The flow of fuel through conduit 74 is also directed to the ignitercontrol 28 by conduit 174.` It passes from conduit 174 through passage318, annular groove 316, passage 172, annular groove 158 and passage 176into chamber 141. It also passes from annular groove 158 through passage162 to passage 164 and through restricting orifice 170 to chamber 166.From chamber 141 the fuel passes through passage 178 into annular groove160. This groove is connected to drain by a passage 180, which has arestricting orifice 184, to permit chamber 141 to become purged of airso that it may be filled with fuel.

When chamber 141 has become filled, the fuel owing into chamber 166through orifice 170 begins to urge piston member 143 to the left againstthe spring 150. This action shuts ofi the supply 9f fuelto chamber 141,shuts off passage 180 from annular groove 160, ports compressordischarge pressure fromconduit 115 by way of passages 154 and 131 tochamber 123 and to the left end of piston member 312 by passage 306,orifice 307 and hole 310, and connects conduit 190 to annular groove 160through annular groove 188. With restriction 307 in passage 306 thecompressor discharge pressure does not reach the left end of pistonmember 312 immediately. However, since chamber 136 is connected tocompressor inlet pressure the pressure differential across piston member124 urges piston member 125 to the right. This action incidentally shutsolf passage 176 from chamber 141 and displaces the fuel in chamber 141forcing it through passage 178, annular grooves 160 and 188 and outconduit 190 to the nozzle 191. When piston 125 is at the left, thespring 133 is designed to be at its free length and exerts no force onthe pistons 125 and 124. Therefore, the initial rate of injection isdetermined by the balance existing between the differential of fuelpressure in chamber 141 and the compressor inlet pressure in chamber 136exerted across piston member 125 and the differential of compressordischarge pressure in chamber 123 and compressor inlet pressure inchamber 136 exerted across piston 124. Since the compressor riseincreases as a function of the increase in engine air flow, thisincrease in pressure difference across piston member 124 must bebalanced by increased pressure in chamber 141 which results in a higherrate of fuel ow through the nozzle 191. By this means, a degree ofaltitude compensation is effected so that the excess fuel/air ratio inthe combustion chamber provided for ignition is kept essentiallyconstant. The amount of fuel injected during each operation of theigniter is determined by the compressor rise and spring 133. Ignition ofthe injected fuel results in ame propagation through the turbine to thetail pipe resulting in ignition in the afterburner of the fuel beingintroduced through nozzles 26.

The ignition of fuel Within the afterburner results in an increase inturbine exhaust gas pressure above that normally obtained withoutafterburning, This increase in pressure is transmitted to the exhaustnozzle actuator control through conduit 79. The control 76 in accordancewith this pressure directs compressor discharge pressure from conduit230 through conduit 262 to the side of the cylinders nearest the nozzlewhich causes the nozzle to open. This pressure is also directed fromconduit 262 by conduit 320 to the right side of piston member 312. Sincerestriction 307 delayed the actuating pressure from reaching the leftside of the piston member 312 before it reached the right side, thespring force of spring 314 keeps piston member 312 in an open position.

The above operation holds when the afterburner ignites. However, if theafterburner fails to ignite, the

.6 turbine exhaust gas pressure would not increase and thel control 76would continue to direct compressor dis charge pressure from conduit 230to conduit 266 to the side of the cylinders furthest from the nozzlewhich causes the nozzle to remain in a closed position. Since compressordischarge pressure is not directed into conduit 262 and therefore notdirected into conduit 320` to the right side of piston 312, there willbe no pressure acting to force piston 312 to the left. Now, whenrestriction 307 has performed its restricting function, the pressure onthe left of piston member 312 will move said piston member to the rightagainst the end of the bore thereby compressing spring 314. This actioncuts off conduit 174 and passageway 318 from passage 172 and the rest ofthe igniter. Spring 150, by virtue of fuel leakage along piston member148 from groove 158 to grooves 192 and 194, will move the piston memberto the right cutting off passage 306 and passage 131 from annular groove156 which contains compressor discharge pressure.

Now piston member 125 is returned to its positionrto the left of Fig. 2by spring 133. The igniter is now in position to inject another chargeof fuel through nozzle 191, as soon as fuel is permitted to enter theigniter.

y p Now piston member 312 which has been restricting the flow of fuelinto the igniter from conduit 174 is moved to the left by spring 314,`the fluid to the left of said piston member being permitted to bleedthrough venting passage 317. As annular groove 316 connects conduit 174and passage 318 to passage 172 and the rest of the igniter, theoperation of the igniter is again set into action.

While the two paragraphs above describe the operation of the igniterwhen the afterburner fails to ignite, action of the igniter is similarwhen after the afterburner has ignited a fiameout occurs. In this eventthe turbine exhaust gas pressure decreases and the control 76 directscompressor discharge pressure from conduit 230 to conduit 266 to theside of the cylinders furthest from the nozzle to cause the nozzle toclose. Since the compressor discharge pressure is not directed intoconduit 262 and therefore not directed into conduit 320 to the rightside of piston 312, there will be no pressure acting to force piston 312to the left. Now, pressure on the left of piston member 312 moves saidpiston member to the right cutting off conduit 174 and passageway 318from passage 172 and the rest of the igniter. The igniter now operatesto reinject a charge of fuel as described above. p

Although a specific igniter control has been shown and described hereinfor the purpose of illustration, it will be evident to those skilled inthe art that the -invention is capable of various modifications andadaptations within the scope of the appended claims. The control systemfor an after-burner as shown in this application is shown and claimed incopending application Serial No. 196,425 of Richard J. Coar et al.,filed November 18, 1950, now Patent No. 2,780,054 issued February 5,1957, and an igniter control of the type shown in this application isshown and claimed in copending application Serial No. 196,402 of CarltonW. Bristol, lr., filed November 18, 1950, now Patent No. 2,780,055issued February 5, 1957.

I claim: y

1. A housing having a chamber for fuel and an inlet and outlet for thechamber, first valve means for controlling the admission of fuel to saidchamber, second valve means for controlling the admission of fuel tosaid first Valve means, means responsive to fuel pressure in saidchamber for closing said first valve means, and piston means to displacefuel from said chamber through said outlet, said first valve meanshaving means for directing fluid under pressure to said piston means toactuate said piston means when said valve means is moved by said fuelpressure, said rst valve means having means for directing ud underpressure to said i lllrllllllllll second valve means to tend to closesaid second valve when said first valve means is moved by said fuelpressure.

2. A housing having a chamber for fuel and an inlet and outlet for thechamber, first valve means for controlling the admission of fuel to saidchamber, means for permitting said chamber to be purged of air by saidfuel so said chamber will become full of fuel, said last named meansincluding a drain conduit connected to said chamber, second valve meansfor controlling the admission of fuel to said first valve means, meansresponsive to fuel pressure in said chamber for closing said first valvemeans, and piston means to displace fuel through said outlet, said firstvalve means having means for directing fluid under pressure to saidpiston means and to one side of said second valve means to close saidsecond valve means and means for connecting said outlet to said chamberand disconnecting said drain conduit from said Ichamber when said valveis moved by said fuel pressure.

3. A housing having a chamber for fuel and an inlet and outlet for thechamber, first valve means for controlling the admission of fuel to saidchamber, means for permitting said chamber to be purged of air by saidfuel so said chamber will become full of fuel, said last named meansincluding a drain conduit connected to said chamber, second valve meansfor' controlling the admission of fuel to said first valve means, saidsecond valve means being biased to an open position, means responsive tofuel pressure in said chamber for closing said rst valve means, andpiston means to displace fuel through said outlet, said first valvemeans having means for directing fluid under pressure to said pistonmeans and to one side of said second valve means to close said secondvalve means and means for connecting said outlet to said chamber anddisconnecting said drain conduit from said chamber when said valve ismoved by said fuel pressure.

4. In combination, a jet engine, means for supplying air to said engine,means for supplying fuel to said engine, means for igniting the fuel-airmixture in the engine formed by said first vand second named means, anafterburner, means for supplying oxygen to said afterburner, means forsupplying fuel to said afterburner, means for igniting the combustiblemixture in the afterburner formed by said fourth and fifth named means,said last named means having piston means for displacing additional fuelinto said engine thereby enriching the fuel-air ratio in the engine,second piston means responsive to the fuel supplied to said a'fterburnerfor controlling said first piston means, and third piston meansresponsive to a pressure under the control of said second piston meansfor controlling the fuel supplied to said second piston means.

5. In combination, a jet engine, means for supplying air to said engine,means for supplying fuel to said engine, means for igniting the fuel-airmixture in the engine formed by said first and second named means, anafterburner, means for supplying oxygen to said afterburner, means forsupplying fuel to said after-burner, and means for igniting thecombustible mixture in the afterburner formed by said .fourth and fifthnamed means, said last named means having piston means including twopistons for displacing additional fuel into said engine therebyenriching the fuel-air ratio in the engine, one piston being large andthe other piston being small, second piston means responsive to the fuelsupplied to said afterburner for controlling said large piston of thefirst piston means, said large piston moving said small piston todisplace the additional fuel, and third piston means re- `sponsive toafterburner ignition for remaining in an open position if afterburnerignition occurs and for moving to a closed position if afterburnerignition does not occur.

6i. A jet engine having a combustion chamber, a turbine downstream ofthe combustion chamber, an afterburner downstream of the turbine, meansfor injecting lfuel into the afterburner, means for supplying oxygen tosaid afterburner, kmeans for igniting the fuel in the afterburnerincluding an auxiliary nozzle in the combustion chamber and means fordischarging a stream of fuel through said nozzle to be ignited andcarried through the turbine into the afterburner, in combination withmeans responsive to pressure variations in the afterburner, and valvemeans responsive to said last means and operative in the absence of anincrease in pressure `for cutting off the supply of fuel to saiddischarging means.

7. An igniter for the fuel in an afterburner including a nozzle for thedischarge of igniter fuel, fuel supply means. plunger means fordelivering fuel from said supply means to said nozzle, valve meanscontrolling the admission of fuel to and the discharge of fuel from saidplunger means, said valve means being movable in response to pressure inthe fuel line for opening the connection from the plunger means to thenozzle, said valve means also operating by its movement to admit iiuidunder pressure to said plunger means for moving it, a normally openvalve between the fuel supply means and the valve means for cutting offthe supply of fuel to said valve means, afterburner pressure responsivemeans for moving said valve into open position, and fuel pressure meansacting in l opposition to said afterburner pressure responsive means formoving said valve into closed position during the operation of theigniter.

8. A housing having a chamber for fuel and an inlet and outletpassageway for the chamber, a third passageway entering said housing, afourth passageway in said housing, first valve means being locatedbetween said third passageway and said fourth passageway, second valvemeans being located between said fourth passageway and said inletpassageway for said chamber, piston means to displace a fiuid in saidchamber through said outlet passageway, a fifth passageway leaving saidhousing, third valve means located between said fifth passageway andsaid outlet passageway for said chamber, a sixth passageway connectingsaid piston means to said first valve means for controlling said means,a seventh passageway entering said housing, fourth valve means locatedin said sixth passageway and connected to said seventh passageway, saidfirst valve means being biased to an open position, said second valvemeans being biased to an open position, said third valve means beingbiased to a closed position, said fourth valve means being biased to aclosed position, means responsive to a pressure in said chamber forclosing said second valve means and opening said third and fourth valvemeans, this action connects the seventh passageway to the sixthpassageway and the second passageway to the fifth passageway anddisconnects said first passageway from said fourth passageway, an eighthpa-ssageway entering said housing, said eighth passageway beingconnected to said first valve means for controlling said means.

9. A housing having a chamber for fuel `and an inlet and outletpassageway for the chamber, a third passageway entering said housing, afourth passageway in said housing, first valve means being locatedbetween said third passageway and said fourth passageway, second valvemeans being located between said fourth passageway and said inletpassageway for said chamber, piston means to displace a iiuid iu saidchamber through said outlet passageway, a fifth passageway leaving saidhousing, third Valve means located` between said fifth passageway andsaid outlet passageway for said chamber, a sixth passageway connectingsaid piston means to said first valve means for controlling said means,a Iseventh passageway entering sa-id housing, fourth valve means locatedin said sixth passageway and connected to said seventh passageway, saidfirst valve means being biased to an open position, said second valvemeans being biased to an open position, said third valve means beingbiased to a closed position, said fourth valve means being biased to aclosed position, means responsive to a pressure in said chamber forclosing said second valve means and opening said third and fourth valvemeans, this action connects the seventh passageway to the sixthpassageway and the second passageway to the fifth passageway anddisconnects said first passageway from said fourth passageway, an eighthpassageway entering said housing, said eighth passageway being connectedto said first valve means for controlling said means, said second, thirdand fourth valve means being interconnected so as to operatesimultaneously.

10. A jet engine including a compressor, a turbine driving thecompressor, a combustion chamber into which air from the compressor isdischarged and from which the products of combustion are delivered tothe turbine, means for supplying fuel to the combustion chamber to beburned with the air therein, and an afterburner connected to the exhaustside of the turbine and into which gas containing oxygen from theturbine is delivered, in combination with means for admitting fuel tothe afterburner to mix with the gas therein, and means for igniting themixture of fuel and gas therein, said last named means including achamber for fuel and an outlet for the chamber, rst valve means forcontrolling the admission of fuel to said chamber, second valve meansfor controlling the admission of fuel to said first valve means, meansresponsive to fuel pressure in said chamber for closing said first valvemeans, and piston means to displace fuel from said chamber through saidoutlet into said combustion chamber, -said first valve means havingmeans for directing fluid under pressure to said piston means when saidvalve means is moved by said fuel pressure, said first valve meanshaving means for directing fluid under pressure to 'said second valvemeans when said first valve means is moved by said fuel pressure.

11. A jet engine including a compressor, a turbine driving thecompressor, a combustion chamber into which air from the compressor isdischarged and from which the products of combustion Eare delivered tothe turbine, means for supplying fuel to the combustion chamber to beburned with the air therein, and an afterburner connected to the exhaustside of the turbine and into which gas containing oxygen from theturbine is delivered, in combination with means for admitting fuel tothe afterburner to mix with the gas therein, and means for igniting themixture of fuel and gas therein, said last named means including achamber for fuel and an outlet for the chamber, .first valve means forcontrolling the admission of fuel to said chamber, second valve meansfor controlling the admission of fuel tosaid first valve means, meansresponsive to fuel pressure in said chamber for closing said irst valvemeans, and piston means to displace fuel from said chamber through saidoutlet into said combustion chamber, said first valve means having meansfor directing air from said compressor to said piston means when lsaidvalve means is moved by said fuel pressure, said first valve meanshaving means for directing air from said compressor to said second valvemeans when said first valve means is moved by said fuel pressure.

l2. A jet engine including a compressor, a turbine driving thecompressor, a combustion chamber into which air from the compressor isdischarged and from which the products of combustion are delivered tothe turbine, means for supplying fuel to the combustion chamber to beburned with the air therein, and an afterburner con-v nected to theexhaust side of the turbine and into which gas containing oxygen fromthe turbine is delivered, in combination with means for admitting fuelto the afterburner to mix with the gas therein, and means for ignitin gthe mixture of fuel and gas therein, said last named means including achamber for fuel with an inlet and outlet, rst valve means responsive tofuel pressure in said chamber for 'controlling the admission of fuel tosaid chamber, second valve means responsive to afterburner ignition forcontrolling the admission of fuel to said first valve means, and pistonmeans to displace fuel from said chamber through said outlet into saidcornbustion chamber.

References Cited in the file of this patent UNITED STATES PATENTS694,187 Pirie et al. Feb. 25, 1902 1,482,467 Harrington Feb. 5, 19241,994,747 Bishop et al. Mar. 19, 1935 2,279,546 Ziegler Apr. 14, 19422,520,967 Schmitt Sept. 5, 1950 2,552,231 Streid et al. May 8, 19512,640,316 Neal June 2, 1953 2,670,033 Ray Feb. 23, 1954 FOREIGN PATENTS211,134 Switzerland Nov. 1, 1940

